Maxforlive poly~ Upsampling

Does using poly~ for upsampling only work when Max is open? I have a patch which is a Roland-style PWM saw (a saw wave ring-modulated by a pulse wave 1 octave higher), but I am using a poly~ to upsample 4x it. The patch works when the Max window is open or if I remove the contents of the poly~ from the poly~.